lect 29: Pulmonary Histology Flashcards
what is respiratory epithelium
pseudo stratified ciliated columnar epithelium
what is the lamina propria
this layer of connective tissue (part of respiratory mucosa that lines the respiratory passageway)
what type of tissue is the submucosa made of
dense irregular connective tissue
what type of epithelium is the nares made of
stratified squamous epithelium continuous with epidermis
what do nares contain
sebaceous glands, sudoriferous glands, hair follicles
what does the mucosa level that begins at the nasal septum include
respiratory epithelium, basement membrane, lamina propria
what are some other names for mucosa
mucoperiosteum, mucoperichondrium, Schneiderin membrane
what type of epithelium is n the nasal cavity roof
pseudo stratified columnar epithelium without goblet cells
what doe basal cells with pigment granules give rise to
they are stem cells- give rise to immature olfactory cells
what does the apical end of the olfactory cells project into
nasal cavity as a knoblike ending with nonmotile cilia
what does the basal end of the cell of the olfactory cell extends into
as an unmyelinated axon that is bundled with other similar axons, through the ethmoid plate to mitral cells located in the olfactory bulb
where are the olfactory glands of bowman located and what do they do
located in lamina propria
secrete odorant-binding protein
odorant-binding protein binds to odorant molecule in nasal cavity
what is the olfactory signal sent by
mitral cells
what is the odorant receptor protein
transmembrane member of the G-protein coupled receptor inserted in the plasma membrane of the modified cilium
what type of epithelium is in the mucosa
respiratory epithelium
what type of tissue is in the submucosa
loose connective tissue
define waldeyer’s ring
ring of lymphoid tissue around nasopharynx
includes tonsils and adenoids
what is the lingual surface of the epiglottis covered with
covered with stratified squamous epithelium
lamina propria with loose CT and elastic fibers
what is the pharyngeal surface of the epiglottis covered with
covered with pseudo stratified ciliated epithelium
lamina propria with tubuloacinar seromucous glands
what does the core of the epiglottis consists of
elastic cartilage
what is the false vocal cords (vestibular folds) covered with
covered with pseudo stratified ciliated epithelium
lamina with seromucous glands
what is the true vocal cords covered with
stratified squamous epithelium
where is hyaline cartilage found in the larynx
thyroid
cricoid
arytenoids
where is elastic cartilage found in the larynx
corniculates
cuneiforms
tips of arytenoids
epiglottis
what type of muscle is in the larynx
skeletal muscle
what type of glands are found in the trachea of the submucosa
many zero-mucous glands
what are the openings between arms of horseshoe-shaped cartilages closed by in the adventitia of the trachea
FECT, mucous membrane, and smooth muscles (trachealis muscles)
what are the bronchi that lie outside the lung
extrapulmonary bronchi
what are segmental bronchi mostly
intrapulmonary
what are segmental bronchi reinforced by
circular rings of hyaline cartilage that transition to irregular plates
what happens as the bronchi become smaller
there is a decrease in the height of the epithelium, a decrease in cartilage and glands, and an increase in the proportion of elastic fibers and smooth muscles
what type of fibers are prominent in the mucosa of the intrapulmonary bronchi
elastic fibers
what is the submucosa of the intrapulmonary bronchi characterized by
characterized by loose CT and lymphatic tissue
contains mixed glands and mucous glands
what does the adventitia of the intrapulmonary bronchi contain
hyaline cartilage plates surrounded by dense FECT
what is absent in bronchioles
absence of cartilage
absence of glands
what are the smallest type of bronchioles
terminal bronchioles
what type of epithelium is characteristic of respiratory bronchioles
epithelium of low columnar to low cuboidal
where does gas exchange typically occur in bronchioles
alveolar outpocketings
what are alveolar ducts
continuations of respiratory bronchioles
what type of epithelium is in alveolar ducts
squamous epithelium
what do the walls of the alveolar ducts consists of
smooth muscle with FECT
what is each alveolar sacs composed of
several alveoli
what are the alveoli within sacs separated by
alveolar septa
what is another name for type 1 and 2 alveolar cells
type 1 and 2 pneumocytes (respectively)
what is the difference between type 1 and type 2 alveolar cells
type 1: less numerous than type 2 and cover largest surface area
type 2: cuboidal or rounded. serve as stem cells for type 1 and type 2 pneumocytes
what are pores of kohn
openings between adjacent alveoli
how are smooth muscle fibers oriented
concentrically, in a spiral fasion
how are elastic fibers oriented
longitudinally
what type of epithelium is in stem cells in the mucosa
basal cells of pseudo stratified epithelium
what are goblet cells in the mucosa
mucous secreting cells
also stem cells; can replace other cells of epithelium
what are neuroendocrine cells
(small granule cells)
may be associated with sensory reception and are more prevalent in infants
release catecholamines
what secretes surfactants
clara cells and type 2 alveolar cells
what is lecithin secreted by and what do they combine with
secreted from apical domain of cells
combine with proteins from clara cells
what does surfactant reduce
surface tension on alveolar surface
what do type 2 alveolar cells phagocytize
old surfactant
what are attributes of type 1 pnemuocytes
very thin cytoplasm
cover about 95% of the alveolar surface
tight junctions connect with other type 1 cells
basal lamina may be fused with basal lamina of nearby capillaries
what are attributes of type 2 pneumocytes
rounded cells that bulge into the alveolar lumen
cover about 5% of the alveolar surface
can divide and replace type 1 pneumocytes
produce phospholipid-protein surfactant that coats alveolar walls
where are clara cells found
only in bronchioles
what happens to the number of clara cells as ciliated columnar cells decreases
they increase
what do clara cells secrete what does does that secretion do
surface-active lipoprotein that prevents collapse of terminal bronchioles during exhalation
what are dust cells derived from
monocytes
what do dust cells phagocytize
particles such as pollutants, bacteria, and surfactant that are not trapped in the muous and expectorate
what is the relation of dust cells to CHF
in CHF, fluid containing the breakdown products of hemoglobin leak into alveolar spaces and are phagocytized by the dust cells
what are the iron-containing dust cells in CHF referred to as
heart failure cells
what are the components of the blood-air barrier
thin capillary endothelium
thin epithelium of pneumocyte
intervening basal lamina produced by both cell types
what does the blood-air barrier permit
permits gas exchange but does not allow fluids or cells to enter alveoli (normally)
